1. Field of the Invention
The present invention relates to paper office supplies, and, in particular, to expandable folders having reinforced sides, corners, and edges for making the file stronger and more durable.
2. Description of the Prior Art
Expandable folders are a necessary tool in the modern office or business and are also used in homes and schools. These folders are typically constructed of rectangular front & rear panel members having accordion-like folds along the sides, commonly called gussets, which allow the folder to expand from front to back. The folders are shipped and stored in their compact state. When put into use they expand gradually as they are filled with documents, papers or other items.
These expandable folders are normally filled with documents until the gussets are completely extended and no additional documents can be placed in the folder. However, filling an expandable folder in this manner often leads to premature failure of the folder due to tearing at certain critical locations. These critical locations are most commonly at the point of intersection of the gusset with the front and rear panel members, at the corners of the folder, along the top edge of the gusset, and in the gusset itself.
Fully expanded folders usually tear at the point of intersection of the gusset with the front and rear panel members because when these expanded folders are subsequently looked through to locate a particular document, the searcher often tries to expand the folder further in order to see and retrieve the documents stored therein. Also, when the retrieved document must be returned to the folder, the searcher will again stretch the folder to make room so that the document may be easily placed therein. However, because the gusset is already fully expanded, the only way for the folder to expand further is for the folder to tear at the point where the gussets are joined to the front and rear panel members of the folder.
A fully expanded folder is also relatively heavy, and this weight contributes to failure of the folder in variety of ways. For instance, the folders are often picked up by only the front or rear panel member, which causes the panel member to completely tear away from the gusset. Further, when a fully expanded folder is repeatedly placed on a desk or tabletop, the rubbing of the corners, sides and bottom of the folder on the tabletop surface causes these areas of the folder to fray or wear away. This fraying and wearing away detracts from the neat appearance the folders should have, further weakens the folder and can cause the loss of small items stored therein. Finally, when a full folder is dropped, the folder will burst or split along the seam between the gusset and front or rear panel members, scattering the folder or contents around the place of impact.
Expandable folders are also normally stored on shelves with their front and rear faces perpendicular to the length of the shelf. When these folders are retrieved, fingers are usually placed over the top edge of the gusset so that the folder can be pulled off the shelf. However, because the fully expanded folder is relatively heavy, pulling the folder in this manner often leads to separation of the gusset from the front and rear panel members. Further, the fingers usually pull the folder from the same place on the gusset over and over again. Over time, dirt and sweat will accumulate on the gusset, thereby fraying and weakening the gusset and causing the gusset to unexpectedly tear when the folder is retrieved.
These folders often become wet during use, either by being exposed to rain or snow during transport from one location to another, or when water or beverages such as coffee, tea, or soda are accidentally spilled on them, or due to moisture in the air when the folder is stored. When these folders become moist or wet, they weaken considerably and are very susceptible to tearing. Further, the wet folders become deformed, weakened and deteriorate rapidly when they become dry, and are also very susceptible to tearing in this condition.
Finally, these folders are often identified by pressure-sensitive adhesive labels attached to the front or rear panel member. However, when it is desired to remove these labels, the folders often become disfigured due to the inability to separate the adhesive on the label from the fibers in the panel members. Thus, these folders are often discarded simply because they no longer have a neat appearance.
The applicants have identified the above problems and have established that a need exists for an expandable folder that solves them. In particular, there is a need for an expandable folder of superior strength that is durable, will not fail when it is filled to capacity, is resistant to liquids, and which will maintain a neat, sturdy appearance.